package fr.mywiki.business.utils;

/**
 * 
 * MD5 in Java JDK Beta-2 written Santeri Paavolainen, Helsinki Finland 1996 (c) Santeri
 * Paavolainen, Helsinki Finland 1996
 * 
 * This library is free software; you can redistribute it and/or modify it under the terms of the
 * GNU Library General Public License as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
 * USA.
 * 
 * See http://www.cs.hut.fi/~santtu/java/ for more information on this class.
 * 
 * This is rather straight re-implementation of the reference implementation given in RFC1321 by
 * RSA.
 * 
 * Passes MD5 test suite as defined in RFC1321.
 * 
 * This Java class has been derived from the RSA Data Security, Inc. MD5 Message-Digest Algorithm
 * and its reference implementation.
 * 
 * $Log: MD5.java,v $
 */

/**
 * Contains internal state of the MD5 class
 */
class MD5State {
	/** 128-byte state */
	int state[];
	/** 64-bit character count (could be true Java long?) */
	int count[];

	/** 64-byte buffer (512 bits) for storing to-be-hashed characters */
	byte buffer[];

	public MD5State() {
		buffer = new byte[64];
		count = new int[2];
		state = new int[4];

		state[0] = 0x67452301;
		state[1] = 0xefcdab89;
		state[2] = 0x98badcfe;
		state[3] = 0x10325476;

		count[0] = count[1] = 0;
	}

	/** Create this State as a copy of another state */
	public MD5State(MD5State from) {
		this();

		int i;

		for (i = 0; i < buffer.length; i++)
			this.buffer[i] = from.buffer[i];

		for (i = 0; i < state.length; i++)
			this.state[i] = from.state[i];

		for (i = 0; i < count.length; i++)
			this.count[i] = from.count[i];
	}
};

/**
 * Implementation of RSA's MD5 hash generator
 * 
 * @version $Revision: 1.3 $
 * @author Santeri Paavolainen <sjpaavol@cc.helsinki.fi>
 */
public class MD5 {
	/** MD5 state */
	MD5State state;

	/**
	 * If Final() has been called, finals is set to the current finals state. Any Update() causes
	 * this to be set to null.
	 */
	MD5State finals;

	/**
	 * Padding for Final()
	 */
	static byte padding[] = { (byte) 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
			0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
			0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

	/**
	 * Initialize MD5 internal state (object can be reused just by calling Init() after every
	 * Final()
	 */
	public synchronized void Init() {
		state = new MD5State();
		finals = null;
	}

	/**
	 * Class constructor
	 */
	public MD5() {
		this.Init();
	}

	/**
	 * Initialize class, and update hash with ob.toString()
	 * 
	 * @param ob Object, ob.toString() is used to update hash after initialization
	 */
	public MD5(Object ob) {
		this();
		Update(ob.toString());
	}

	private int rotate_left(int x, int n) {
		return (x << n) | (x >>> (32 - n));
	}

	private int uadd(int a, int b) {
		long aa, bb;
		aa = ((long) a) & 0xffffffffL;
		bb = ((long) b) & 0xffffffffL;

		aa += bb;

		return (int) (aa & 0xffffffffL);
	}

	private int uadd(int a, int b, int c) {
		return uadd(uadd(a, b), c);
	}

	private int uadd(int a, int b, int c, int d) {
		return uadd(uadd(a, b, c), d);
	}

	private int FF(int a, int b, int c, int d, int x, int s, int ac) {
		a = uadd(a, ((b & c) | (~b & d)), x, ac);
		return uadd(rotate_left(a, s), b);
	}

	private int GG(int a, int b, int c, int d, int x, int s, int ac) {
		a = uadd(a, ((b & d) | (c & ~d)), x, ac);
		return uadd(rotate_left(a, s), b);
	}

	private int HH(int a, int b, int c, int d, int x, int s, int ac) {
		a = uadd(a, (b ^ c ^ d), x, ac);
		return uadd(rotate_left(a, s), b);
	}

	private int II(int a, int b, int c, int d, int x, int s, int ac) {
		a = uadd(a, (c ^ (b | ~d)), x, ac);
		return uadd(rotate_left(a, s), b);
	}

	private int[] Decode(byte buffer[], int len, int shift) {
		int out[];
		int i, j;

		out = new int[16];

		for (i = j = 0; j < len; i++, j += 4) {
			out[i] = ((int) (buffer[j + shift] & 0xff))
					| (((int) (buffer[j + 1 + shift] & 0xff)) << 8)
					| (((int) (buffer[j + 2 + shift] & 0xff)) << 16)
					| (((int) (buffer[j + 3 + shift] & 0xff)) << 24);
		}
		return out;
	}

	private void Transform(MD5State state, byte buffer[], int shift) {
		int a = state.state[0], b = state.state[1], c = state.state[2], d = state.state[3], x[];

		x = Decode(buffer, 64, shift);

		/* Round 1 */
		a = FF(a, b, c, d, x[0], 7, 0xd76aa478); /* 1 */
		d = FF(d, a, b, c, x[1], 12, 0xe8c7b756); /* 2 */
		c = FF(c, d, a, b, x[2], 17, 0x242070db); /* 3 */
		b = FF(b, c, d, a, x[3], 22, 0xc1bdceee); /* 4 */
		a = FF(a, b, c, d, x[4], 7, 0xf57c0faf); /* 5 */
		d = FF(d, a, b, c, x[5], 12, 0x4787c62a); /* 6 */
		c = FF(c, d, a, b, x[6], 17, 0xa8304613); /* 7 */
		b = FF(b, c, d, a, x[7], 22, 0xfd469501); /* 8 */
		a = FF(a, b, c, d, x[8], 7, 0x698098d8); /* 9 */
		d = FF(d, a, b, c, x[9], 12, 0x8b44f7af); /* 10 */
		c = FF(c, d, a, b, x[10], 17, 0xffff5bb1); /* 11 */
		b = FF(b, c, d, a, x[11], 22, 0x895cd7be); /* 12 */
		a = FF(a, b, c, d, x[12], 7, 0x6b901122); /* 13 */
		d = FF(d, a, b, c, x[13], 12, 0xfd987193); /* 14 */
		c = FF(c, d, a, b, x[14], 17, 0xa679438e); /* 15 */
		b = FF(b, c, d, a, x[15], 22, 0x49b40821); /* 16 */

		/* Round 2 */
		a = GG(a, b, c, d, x[1], 5, 0xf61e2562); /* 17 */
		d = GG(d, a, b, c, x[6], 9, 0xc040b340); /* 18 */
		c = GG(c, d, a, b, x[11], 14, 0x265e5a51); /* 19 */
		b = GG(b, c, d, a, x[0], 20, 0xe9b6c7aa); /* 20 */
		a = GG(a, b, c, d, x[5], 5, 0xd62f105d); /* 21 */
		d = GG(d, a, b, c, x[10], 9, 0x2441453); /* 22 */
		c = GG(c, d, a, b, x[15], 14, 0xd8a1e681); /* 23 */
		b = GG(b, c, d, a, x[4], 20, 0xe7d3fbc8); /* 24 */
		a = GG(a, b, c, d, x[9], 5, 0x21e1cde6); /* 25 */
		d = GG(d, a, b, c, x[14], 9, 0xc33707d6); /* 26 */
		c = GG(c, d, a, b, x[3], 14, 0xf4d50d87); /* 27 */
		b = GG(b, c, d, a, x[8], 20, 0x455a14ed); /* 28 */
		a = GG(a, b, c, d, x[13], 5, 0xa9e3e905); /* 29 */
		d = GG(d, a, b, c, x[2], 9, 0xfcefa3f8); /* 30 */
		c = GG(c, d, a, b, x[7], 14, 0x676f02d9); /* 31 */
		b = GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); /* 32 */

		/* Round 3 */
		a = HH(a, b, c, d, x[5], 4, 0xfffa3942); /* 33 */
		d = HH(d, a, b, c, x[8], 11, 0x8771f681); /* 34 */
		c = HH(c, d, a, b, x[11], 16, 0x6d9d6122); /* 35 */
		b = HH(b, c, d, a, x[14], 23, 0xfde5380c); /* 36 */
		a = HH(a, b, c, d, x[1], 4, 0xa4beea44); /* 37 */
		d = HH(d, a, b, c, x[4], 11, 0x4bdecfa9); /* 38 */
		c = HH(c, d, a, b, x[7], 16, 0xf6bb4b60); /* 39 */
		b = HH(b, c, d, a, x[10], 23, 0xbebfbc70); /* 40 */
		a = HH(a, b, c, d, x[13], 4, 0x289b7ec6); /* 41 */
		d = HH(d, a, b, c, x[0], 11, 0xeaa127fa); /* 42 */
		c = HH(c, d, a, b, x[3], 16, 0xd4ef3085); /* 43 */
		b = HH(b, c, d, a, x[6], 23, 0x4881d05); /* 44 */
		a = HH(a, b, c, d, x[9], 4, 0xd9d4d039); /* 45 */
		d = HH(d, a, b, c, x[12], 11, 0xe6db99e5); /* 46 */
		c = HH(c, d, a, b, x[15], 16, 0x1fa27cf8); /* 47 */
		b = HH(b, c, d, a, x[2], 23, 0xc4ac5665); /* 48 */

		/* Round 4 */
		a = II(a, b, c, d, x[0], 6, 0xf4292244); /* 49 */
		d = II(d, a, b, c, x[7], 10, 0x432aff97); /* 50 */
		c = II(c, d, a, b, x[14], 15, 0xab9423a7); /* 51 */
		b = II(b, c, d, a, x[5], 21, 0xfc93a039); /* 52 */
		a = II(a, b, c, d, x[12], 6, 0x655b59c3); /* 53 */
		d = II(d, a, b, c, x[3], 10, 0x8f0ccc92); /* 54 */
		c = II(c, d, a, b, x[10], 15, 0xffeff47d); /* 55 */
		b = II(b, c, d, a, x[1], 21, 0x85845dd1); /* 56 */
		a = II(a, b, c, d, x[8], 6, 0x6fa87e4f); /* 57 */
		d = II(d, a, b, c, x[15], 10, 0xfe2ce6e0); /* 58 */
		c = II(c, d, a, b, x[6], 15, 0xa3014314); /* 59 */
		b = II(b, c, d, a, x[13], 21, 0x4e0811a1); /* 60 */
		a = II(a, b, c, d, x[4], 6, 0xf7537e82); /* 61 */
		d = II(d, a, b, c, x[11], 10, 0xbd3af235); /* 62 */
		c = II(c, d, a, b, x[2], 15, 0x2ad7d2bb); /* 63 */
		b = II(b, c, d, a, x[9], 21, 0xeb86d391); /* 64 */

		state.state[0] += a;
		state.state[1] += b;
		state.state[2] += c;
		state.state[3] += d;
	}

	/**
	 * Updates hash with the bytebuffer given (using at maximum length bytes from that buffer)
	 * 
	 * @param state Which state is updated
	 * @param buffer Array of bytes to be hashed
	 * @param offset Offset to buffer array
	 * @param length Use at maximum `length' bytes (absolute maximum is buffer.length)
	 */
	public void Update(MD5State stat, byte buffer[], int offset, int length) {
		int index, partlen, i, start;

		/*
		 * System.out.print("Offset = " + offset + "\tLength = " + length + "\t");
		 * System.out.print("Buffer = "); for (i = 0; i < buffer.length; i++) System.out.print((int)
		 * (buffer[i] & 0xff) + " "); System.out.print("\n");
		 */

		finals = null;

		/* Length can be told to be shorter, but not inter */
		if ((length - offset) > buffer.length)
			length = buffer.length - offset;

		/* compute number of bytes mod 64 */
		index = (int) (stat.count[0] >>> 3) & 0x3f;

		if ((stat.count[0] += (length << 3)) < (length << 3))
			stat.count[1]++;

		stat.count[1] += length >>> 29;

		partlen = 64 - index;

		if (length >= partlen) {
			for (i = 0; i < partlen; i++)
				stat.buffer[i + index] = buffer[i + offset];

			Transform(stat, stat.buffer, 0);

			for (i = partlen; (i + 63) < length; i += 64)
				Transform(stat, buffer, i);

			index = 0;
		} else i = 0;

		/* buffer remaining input */
		if (i < length) {
			start = i;
			for (; i < length; i++)
				stat.buffer[index + i - start] = buffer[i + offset];
		}
	}

	/**
	 * Plain update, updates this object
	 */
	public void Update(byte buffer[], int offset, int length) {
		Update(this.state, buffer, offset, length);
	}

	public void Update(byte buffer[], int length) {
		Update(this.state, buffer, 0, length);
	}

	/**
	 * Updates hash with given array of bytes
	 * 
	 * @param buffer Array of bytes to use for updating the hash
	 */
	public void Update(byte buffer[]) {
		Update(buffer, 0, buffer.length);
	}

	/**
	 * Updates hash with a single byte
	 * 
	 * @param b Single byte to update the hash
	 */
	public void Update(byte b) {
		byte buffer[] = new byte[1];
		buffer[0] = b;

		Update(buffer, 1);
	}

	/**
	 * Update buffer with given string.
	 * 
	 * @param s String to be update to hash (is used as s.getBytes())
	 */
	public void Update(String s) {
		byte chars[];

		chars = new byte[s.length()];
		// GEORGIOS //s.getBytes(0, s.length(), chars, 0);
		s.getBytes();
		// GEORGIOS //
		Update(chars, chars.length);
	}

	/**
	 * Update buffer with a single integer (only & 0xff part is used, as a byte)
	 * 
	 * @param i Integer value, which is then converted to byte as i & 0xff
	 */

	public void Update(int i) {
		Update((byte) (i & 0xff));
	}

	private byte[] Encode(int input[], int len) {
		int i, j;
		byte out[];

		out = new byte[len];

		for (i = j = 0; j < len; i++, j += 4) {
			out[j] = (byte) (input[i] & 0xff);
			out[j + 1] = (byte) ((input[i] >>> 8) & 0xff);
			out[j + 2] = (byte) ((input[i] >>> 16) & 0xff);
			out[j + 3] = (byte) ((input[i] >>> 24) & 0xff);
		}

		return out;
	}

	/**
	 * Returns array of bytes (16 bytes) representing hash as of the current state of this object.
	 * Note: getting a hash does not invalidate the hash object, it only creates a copy of the real
	 * state which is finalized.
	 * 
	 * @return Array of 16 bytes, the hash of all updated bytes
	 */
	public synchronized byte[] Final() {
		byte bits[];
		int index, padlen;
		MD5State fin;

		if (finals == null) {
			fin = new MD5State(state);

			bits = Encode(fin.count, 8);

			index = (int) ((fin.count[0] >>> 3) & 0x3f);
			padlen = (index < 56) ? (56 - index) : (120 - index);

			Update(fin, padding, 0, padlen);
			/**/
			Update(fin, bits, 0, 8);

			/* Update() sets finalds to null */
			finals = fin;
		}

		return Encode(finals.state, 16);
	}

	/**
	 * Turns array of bytes into string representing each byte as unsigned hex number.
	 * 
	 * @param hash Array of bytes to convert to hex-string
	 * @return Generated hex string
	 */
	public static String asHex(byte hash[]) {
		StringBuffer buf = new StringBuffer(hash.length * 2);
		int i;

		for (i = 0; i < hash.length; i++) {
			if (((int) hash[i] & 0xff) < 0x10)
				buf.append("0");

			buf.append(Long.toString((int) hash[i] & 0xff, 16));
		}

		return buf.toString();
	}

	/**
	 * Returns 32-character hex representation of this objects hash
	 * 
	 * @return String of this object's hash
	 */
	public String asHex() {
		return asHex(this.Final());
	}
}
